#include <stdio.h>

#include <string.h>

#include <stdlib.h>

static int

do_test (void)

{

  size_t size;

  char *buf;

  FILE *fp = open_memstream (&buf, &size);

  if (fp == NULL)

    {

      puts ("open_memstream failed");

      return 1;

    }

  off64_t off = ftello64 (fp);

  if (off != 0)

    {

      puts ("initial position wrong");

      return 1;

    }

  if (fseek (fp, 32768, SEEK_SET) != 0)

    {

      puts ("fseek failed");

      return 1;

    }

  if (fputs ("foo", fp) == EOF)

    {

      puts ("fputs failed");

      return 1;

    }

  if (fclose (fp) == EOF)

    {

      puts ("fclose failed");

      return 1;

    }

  if (size != 32768 + 3)

    {

      printf ("expected size %d, got %zu\n", 32768 + 3, size);

      return 1;

    }

  for (int i = 0; i < 32768; ++i)

    if (buf[i] != '\0')

      {

	printf ("byte at offset %d is %#hhx\n", i, buf[i]);

	return 1;

      }

  if (memcmp (buf + 32768, "foo", 3) != 0)

    {

      puts ("written string incorrect");

      return 1;

    }

  /* Mark the buffer.  */

  memset (buf, 'A', size);

  free (buf);

  /* Try again, this time with write mode enabled before the seek.  */

  fp = open_memstream (&buf, &size);

  if (fp == NULL)

    {

      puts ("2nd open_memstream failed");

      return 1;

    }

  off = ftello64 (fp);

  if (off != 0)

    {

      puts ("2nd initial position wrong");

      return 1;

    }

  if (fputs ("bar", fp) == EOF)

    {

      puts ("2nd fputs failed");

      return 1;

    }

  if (fseek (fp, 32768, SEEK_SET) != 0)

    {

      puts ("2nd fseek failed");

      return 1;

    }

  if (fputs ("foo", fp) == EOF)

    {

      puts ("3rd fputs failed");

      return 1;

    }

  if (fclose (fp) == EOF)

    {

      puts ("2nd fclose failed");

      return 1;

    }

  if (size != 32768 + 3)

    {

      printf ("2nd expected size %d, got %zu\n", 32768 + 3, size);

      return 1;

    }

  if (memcmp (buf, "bar", 3) != 0)

    {

      puts ("initial string incorrect in 2nd try");

      return 1;

    }

  for (int i = 3; i < 32768; ++i)

    if (buf[i] != '\0')

      {

	printf ("byte at offset %d is %#hhx in 2nd try\n", i, buf[i]);

	return 1;

      }

  if (memcmp (buf + 32768, "foo", 3) != 0)

    {

      puts ("written string incorrect in 2nd try");

      return 1;

    }

  return 0;

}

#define TEST_FUNCTION do_test ()

#include "../test-skeleton.c"